My 4K 60hz monitor has recently started giving me this result on a frame skip test, at stock resolution/refresh rate. I haven't seen it in any examples before and was hoping someone could explain what it means.

To give some background, I originally came across the frame skip test when trying to overclock my monitor. Unfortunately, even a 1hz overclock caused the monitor to frameskip at all resolutions. However, 60hz used to be fine - it gave a perfect result.

Recently, I decided to revisit the frame skip test and am getting this weird result at stock refresh rate. The result is the same across resolutions.

It only displays like this on under 10% of the pictures I take on my phone camera. I have tested my phone camera (galaxy s8+) with other screens and the phone camera is working fine.

Computer side:Browser and compositor VSYNC is disabled (e.g. some Linux installs) -- This can also happen with chrome --disable-gpu-vsync but the fact there is no sync error message, is that your monitor's frame buffer is tearing!

Monitor side:I've seen this happen monitor-side, but it's ultra-rare when it happens. Usually tearing is GPU side but it can happen to the monitor frame buffer too if there's a bug, failure, or some other weird situation -- like during overclocking.

Probably the latter. Yes, it is very weird when monitor-side tearing happens. That should never happen, but it can happen when things start to bug out (e.g. overclocking).

Computer side:Browser and compositor VSYNC is disabled (e.g. some Linux installs) -- This can also happen with chrome --disable-gpu-vsync but the fact there is no sync error message, is that your monitor's frame buffer is tearing!

Monitor side:I've seen this happen monitor-side, but it's ultra-rare when it happens. Usually tearing is GPU side but it can happen to the monitor frame buffer too if there's a bug, failure, or some other weird situation -- like during overclocking.

Probably the latter. Yes, it is very weird when monitor-side tearing happens. That should never happen, but it can happen when things start to bug out (e.g. overclocking).

Thanks both! This is really insightful.

I'm using Windows 10, Chrome. When I get access to the monitor again on Monday, I plan to test it out with my laptop to see if the same issue persists. Will report back.

Assuming that it is a monitor problem, what is the best way to explain this to the warranty rep on the phone? I would imagine saying there is a 'frame buffer problem' is a hard thing to explain to a layman ...

Please bear in mind that I don't overclock the monitor. When I first got it, I tried, but even a 1hz overclock resulted in frame skipping so since then I didn't bother. I've tested it a few times since (without overclocking) and it was fine.

AzTec wrote:Assuming that it is a monitor problem, what is the best way to explain this to the warranty rep on the phone? I would imagine saying there is a 'frame buffer problem' is a hard thing to explain to a layman ...

Please bear in mind that I don't overclock the monitor. When I first got it, I tried, but even a 1hz overclock resulted in frame skipping so since then I didn't bother. I've tested it a few times since (without overclocking) and it was fine.

If the monitor returns to normal when you put it back to normal Hz (e.g. 60 Hz) then there's no warranty problem. It's just simply your monitor is one of those that isn't very overclock-friendly.

If it is back to normal now, then you don't need to talk to the warranty rep (unless there's a different problem?). Glitches that only occur during overclocking are typically not covered by warranty. You just simply stop overclocking and everything is back to normal, with no warranty problems.

If you used ToastyX CRU to overclock, and this is still happening after you removed the overclock -- then you need to reset by running "reset-all.exe" that came with ToastyX CRU. That should fix things.

Monitor-side tearing can still happen at non-overclocked 60 Hz if you're using custom timings -- e.g. unsupported Totals / Sync / Porches / (blanking intervals) -- so reinstalling graphics drivers and/or running reset-all.exe -- can clear these from Windows if the problem is still happening after you stopped overclocking the monitor.

Monitor overclocking headroom varies a lot. 1 Hz can make a monitor give a huge fuss in a glitchmess (60Hz refuses to overclock to 61Hz), while others will duke it out to even a 200% overclock margin (e.g. 60Hz overclocked successfully to 180Hz). Displays have notoroiously unpredictable overclocking margins. Generally, it's the monitors that have no OSD electronics or timings watchdog ("OUT OF RANGE" messages) that overclock better -- and sometimes that's certain kinds of laptop LCDs which often have a lower resolution so more dotclock overclock headroom in some cases -- so ironically, some laptop LCDs overclock better. Not always -- but this is where we got the "60Hz overclocked to 180Hz" report!

AzTec wrote:Assuming that it is a monitor problem, what is the best way to explain this to the warranty rep on the phone? I would imagine saying there is a 'frame buffer problem' is a hard thing to explain to a layman ...

Please bear in mind that I don't overclock the monitor. When I first got it, I tried, but even a 1hz overclock resulted in frame skipping so since then I didn't bother. I've tested it a few times since (without overclocking) and it was fine.

If the monitor returns to normal when you put it back to normal Hz (e.g. 60 Hz) then there's no warranty problem. It's just simply your monitor is one of those that isn't very overclock-friendly.

If it is back to normal now, then you don't need to talk to the warranty rep (unless there's a different problem?). Glitches that only occur during overclocking are typically not covered by warranty. You just simply stop overclocking and everything is back to normal, with no warranty problems.

If you used ToastyX CRU to overclock, and this is still happening after you removed the overclock -- then you need to reset by running "reset-all.exe" that came with ToastyX CRU. That should fix things.

Monitor-side tearing can still happen at non-overclocked 60 Hz if you're using custom timings -- e.g. unsupported Totals / Sync / Porches / (blanking intervals) -- so reinstalling graphics drivers and/or running reset-all.exe -- can clear these from Windows if the problem is still happening after you stopped overclocking the monitor.

Monitor overclocking headroom varies a lot. 1 Hz can make a monitor give a huge fuss in a glitchmess (60Hz refuses to overclock to 61Hz), while others will duke it out to even a 200% overclock margin (e.g. 60Hz overclocked successfully to 180Hz). Displays have notoroiously unpredictable overclocking margins. Generally, it's the monitors that have no OSD electronics or timings watchdog ("OUT OF RANGE" messages) that overclock better -- and sometimes that's certain kinds of laptop LCDs which often have a lower resolution so more dotclock overclock headroom in some cases -- so ironically, some laptop LCDs overclock better. Not always -- but this is where we got the "60Hz overclocked to 180Hz" report!

Thanks but I think there's a misunderstanding. I am not overclocking the monitor and never have, except for a brief 30 minutes of testing when I first received the monitor a couple of months ago. The monitor has had no frame skipping or tearing since then until now.

This tearing is happening at stock resolution/refresh rate. It is happening at all resolutions with the stock refresh rate of 60hz.

Yes Chrome vsync being disabled can do the same thing in chrome://flagsSurprising that the frameskip software didn't detect this, it should have. What framerate was it running at? I'll need to improve my TestUFO heuristics to detect these situations.

Glad you figured it out!

For future readers of this thread:-- Don't use chrome --disable-gpu-vsync-- Don't disable VSYNC in chrome://flags